Novel prostate cancer vaccine taking aim at cancer cell 'sweet spot'

Jan 08, 2009

Molecules of sugar sitting on the surface of cancer cells are keys to the development of a new vaccine aimed at both treating and stopping the spread of certain types of cancers called carcinomas, which include prostate, breast, ovarian and lung, among others. Armed with a new two-year grant for $600,000 from the Gateway for Cancer Research, an Illinois-based philanthropic foundation, immunologist Alessandra Franco, M.D., Ph.D., and her co-workers at the Moores Cancer Center at the University of California, San Diego are hoping to develop a low-cost immunotherapy for prostate carcinoma that may also have use against a variety of other carcinomas as well.

Franco, adjunct assistant professor of pediatrics at the UC San Diego School of Medicine, and her co-workers have spent the last decade proving that the immune system's destructive, or "killer," T-cells can recognize sugars on tumor cell surfaces. Her laboratory pioneered and developed the notion that conventional T-cells recognize not only peptides, or pieces of proteins, but also sugars, specifically small carbohydrates called tumor-associated carbohydrate antigens (TACA) expressed on carcinoma cell surfaces. Ideally, this recognition enables the T-cell to attach to and kill the cancer cell.

The researchers have designed "glycopeptides," compounds in which sugars are linked to peptides that are recognized by T-cells. When given as part of a vaccine therapy, these glycopeptides rouse immune system T-cells into recognizing TACA on tumor cell surfaces, attacking and killing the cancer cells. Her research team has already shown that both normal mice and mice with tumors that were vaccinated could successfully generate carbohydrate-specific T-cells that could kill tumors expressing the same carbohydrate molecule.

Cancer vaccines have had a mixed record of success at best. Most immunotherapies have focused on revving up immune system antibodies to recognize proteins on tumor cells.

"A limitation with current immunotherapies is that every tumor expresses different protein antigens, which all need to be characterized," she explained. "It is difficult for the immune system to discriminate, to tell that cancer cells are 'non-self' and should be destroyed. What's nice about T-cells recognizing sugars and why it's so important in cancer is because the same molecules are uniquely expressed in a large variety of cancers." A cell that becomes cancerous begins making a variety of sugar molecules that are not expressed in normal adult cells, making this strategy potentially useful for wide-ranging treatments of different tumors. Her team is targeting a sugar that is expressed on all carcinomas, a type of cancer that begins in epithelial cells.

Studies in the first year of the grant are focusing on gathering further laboratory and preclinical data to show the vaccine's effectiveness. Franco is hoping to begin a clinical trial in the second year of the grant to test the vaccine on prostate cancer patients who have already had treatment but who are at extremely high risk for relapse. She sees the vaccine as being used to help prevent the spread of cancer (metastatic disease), and perhaps even in preventing cancer in healthy people.

"The beauty of this approach is that the same vaccine may prevent metastasis," she said, noting that tumor cells can use sugar or carbohydrate antigens to spread. "If ultimately proven successful, this could be used in a first attempt to try to address vaccination on a large scale to prevent cancer."

The same type of vaccine can potentially be used for breast, lung, liver, ovary and other carcinomas, Franco said. "If we can show that this system works in humans, we think that it can address a variety of tumors with the same sugar compounds." The vaccine's relatively simple formulation, stability and low production cost could make it ideal for use in developing countries, she added.

Source: University of California - San Diego

Explore further: Lanreotide improves survival with enteropancreatic tumors

add to favorites email to friend print save as pdf

Related Stories

First cancer immunotherapy for dogs developed

Jul 04, 2014

Nearly every second dog develops cancer from the age of ten years onward. A few therapies derived from human medicine are available for dogs. A very successful form of therapy by which antibodies inhibit ...

Antibodies from the desert as guides to diseased cells

Jun 12, 2014

Nanoparticles are considered a promising approach in detecting and fighting tumour cells. The method has, however, often failed because the human immune system recognizes and rejects them before they can ...

DNA nanorobot triggers targeted therapeutic responses

Feb 16, 2012

Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University have developed a robotic device made from DNA that could potentially seek out specific cell targets within a complex ...

The promise and peril of nanotechnology

Mar 26, 2014

Scientists at Northwestern University have found a way to detect metastatic breast cancer by arranging strands of DNA into spherical shapes and using them to cover a tiny particle of gold, creating a "nano-flare" ...

Recommended for you

Cancerous tumors may spread by pure chance

6 hours ago

The spreading of a cancerous tumor from one part of the body to another may occur through pure chance instead of key genetic mutations, a new study has shown.

Lanreotide improves survival with enteropancreatic tumors

23 hours ago

(HealthDay)—Lanreotide significantly improves survival among patients with metastatic enteropancreatic neuroendocrine tumors (grade 1 or 2), according to a study published in the July 17 issue of the New En ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

E_L_Earnhardt
not rated yet Jan 09, 2009
Fine, but you are still trying to KILL it - not CURE it! If you drain off the ENERGY SURPLUS the cell can live out its normal life, mitosing at a normal rate. How do you DO this? Just COOL it! That is what angiogenesis is trying to do!